1. Field of the Invention
This invention relates to electrically operated toothbrushes, and more particularly to an improved electrically operated toothbrush having multiple rotary brushes for simultaneously cleaning and massaging multiple tooth and gum surfaces.
2. Description of the Prior Art
Various devices for cleaning and treating the oral cavity have been proposed in which one or more power driven rotary brushes are provided for massaging the gums and cleaning the teeth. Many of these prior art devices have employed a brushing action transversely of the teeth, or generally parallel to the gum line, although it has long been recognized that a brushing action longitudinally of the teeth and away from the gum line is preferred to the exclusive use of a transverse brushing action.
It is also known, for example from U.S. Pat. No. 2,628,377, to provide a driven rotary toothbrush assembly wherein three rotary brushes are mounted for rotation about parallel axes in position to simultaneously engage inner, outer, and bite surfaces of the teeth, with a gear drive arrangement being provided to rotate the brushes engaging the side tooth surfaces in a direction to brush each surface longitudinally of the teeth and away from the gums. However, the toothbrush disclosed in this patent is very bulky and difficult to maneuver in the mouth. Further, the apparatus does not readily lend itself to use by a plurality of persons in that the brushes and brush supports require tools for removal and the brushes are each supported for separate replacement.